A quality analyst wants to construct a control chart for determining whether four machines, all producing the same product, are in control with regard to a particular quality attribute. Accordingly, she inspected 1,000 units of output from each machine in random samples, with the following results: $$\begin{array} { c c }
\text { Machine } & \text { Total Defectives } \
\hline \# 1 & 23 \
\# 2 & 15 \
\# 3 & 29 \
\# 4 & 13
\end{array}$$
What is the sample proportion of defectives for machine #1?
A) .023
B) .02
C) .0115
D) .0058
E) .005

Question

A quality analyst wants to construct a control chart for determining whether four machines, all producing the same product, are in control with regard to a particular quality attribute. Accordingly, she inspected 1,000 units of output from each machine in random samples, with the following results: $$\begin{array} { c c } 
\text { Machine } & \text { Total Defectives } \
\hline \# 1 & 23 \
\# 2 & 15 \
\# 3 & 29 \
\# 4 & 13
\end{array}$$
What is the sample proportion of defectives for machine #1?
A) .023
B) .02
C) .0115
D) .0058
E) .005

Quizplus · Accepted Answer

The sample proportion of defectives for machine #1 is 23/1000 = 0.023.

A Quality Analyst Wants to Construct a Control Chart for Determining